Increased frequency of IFN-γ-producing peripheral CD8+ T cells with memory-phenotype in patients with chronic hepatitis C

✍ Scribed by Masayuki Murata; Shigeki Nabeshima; Naoyasu Maeda; Hisashi Nakashima; Seizaburo Kashiwagi; Jun Hayashi

• Publisher: John Wiley and Sons
• Year: 2002
• Tongue: English
• Weight: 141 KB
• Volume: 67
• Category: Article
• ISSN: 0146-6615
• DOI: 10.1002/jmv.2205

✦ Synopsis

Abstract

To identify the capacity for cytokine production and the phenotypic characteristics of peripheral CD8^+^ T cells in patients with chronic hepatitis C, 31 patients with chronic hepatitis C and 22 healthy controls were studied at the single cell level by three‐color flow cytometry. Whole blood was stained with surface CD8, intracellular interferon‐γ (IFN‐γ), and interleukin‐4 (IL‐4), surface CD8, CD28, and intracellular IFN‐γ after stimulation with PMA plus ionomycin, and then surface CD8, CD45RA, and CD28. IFN‐γ‐producing peripheral CD8^+^ T cells were found frequently in patients than in controls (P < 0.05), whereas IL‐4‐producing peripheral CD8^+^ T cells were not. Although the frequency of peripheral CD28^+^CD8^+^ and CD28^−^CD8^+^ T cells in patients was not different from that of controls, CD28^+^CD8^+^ T cells exceeded CD28^−^CD8^+^ T cells in the capacity for IFN‐γ‐production after mitogenic stimulation (P < 0.01). In a more detailed analysis of the CD28^+^CD8^+^ T cells, CD45RA^−^CD28^+^CD8^+^ T cells, defined phenotypically as memory cells, were found frequently in patients than in controls (P < 0.05). There were no significant correlations between the frequency of IFN‐γ‐producing peripheral CD8^+^ T cells and hepatitis C virus RNA level or serum alanine aminotransferase level in patients. These data suggest that functionally T cytotoxic type 1 and memory CD8^+^ T cells are predominant in the peripheral blood of chronic hepatitis C patients and that such activated CD8^+^ T cells are associated with liver damage. J. Med. Virol. 67:162–170, 2002. © 2002 Wiley‐Liss, Inc.